Published in the journal PLOS ONE, the study showed that tackling unhealthy lifestyle factors would provide the greatest benefit in increasing life expectancy among those with SMI. In particular, interventions that aim to stop smoking among people with schizophrenia and approaches to lessen sedentary behaviour among people with bipolar disorders appear to be the most promising ways to increase life expectancy, showing an increase of 2 years 5 months and an increase of one year 3 months respectively.
Currently people with SMI tend to live on average 12 to 15 years less than those in the general population. 80% of deaths of those with SMI are caused by common diseases such as heart disease, respiratory illnesses, diabetes, cancer and digestive disorders. All these diseases can be partly attributed to unhealthy lifestyle factors, social isolation and deprivation, and inadequate use of healthcare services. To inform public health policy, the study aimed to estimate how much tackling these changeable factors in the lives of people with SMI could translate into a gain in life expectancy.
Using data from systemic reviews, the researchers estimated the level of association between a range of different risk factors and the total number of deaths amongst those with SMI. The factors were categorised into three groups: behavioural risk factors such as smoking and physical inactivity, healthcare risk factors such as uptake of treatment and access to healthcare resources and social risk factors such as stigma and exclusion.
By considering the effectiveness of interventions aimed at changing these factors the researchers then calculated the gains in life expectancy that could occur. Examples of interventions to address the risk factors were smoking cessation initiatives, improving access to anti-psychotic medication and educative approaches to reduce stigma.
The analysis estimated that approaches that tackled all these factors could produce a potential gain in life expectancy from birth of four years for those with bipolar disorders and seven years for those with schizophrenia. Gains in life expectancies were also estimated later in life and at 65 years the projected gain was three years for bipolar disorder and four years for schizophrenia.
Lead author, Dr Alex Dregan from the Institute of Psychiatry, Psychology & Psychiatry, King's College London said: 'Our study shows that by addressing the health behaviours, healthcare engagement and social issues of people with severe mental illness we could potentially increase their life expectancy by about 4 to 7 years. The analysis indicates that, when considering different approaches to help those with severe mental illness, the whole is greater than the sum of the parts and there is more benefit if a multi-faceted approach is taken which addresses behaviour, healthcare and social issues simultaneously. Greater investments in developing more effective interventions aimed at reducing unhealthy behaviours and treating the underlying symptoms would contribute to reducing the gap in premature mortality between those with severe mental illness and the general population.'
Reference: Dregan et al. (2020) Potential gains in life expectancy from reducing amenable mortality among people diagnosed with serious mental illness in the United Kingdom, PLOS ONE